Mood, attention and motivation co-vary with activity in the neuromodulatory systems of the brain to influence behaviour. These psychological states, mediated by neuromodulators, have a profound influence on the cognitive processes of attention, perception and, particularly, our ability to retrieve memories from the past and make new ones. Moreover, many psychiatric and neurodegenerative disorders are related to dysfunction of these neuromodulatory systems. Neurons of the brainstem nucleus locus coeruleus are the sole source of noradrenaline, a neuromodulator that has a key role in all of these forebrain activities. Elucidating the factors that control the activity of these neurons and the effect of noradrenaline in target regions is key to understanding how the brain allocates attention and apprehends the environment to select, store and retrieve information for generating adaptive behaviour.

Mood, motivation, attention, and arousal are behavioral states having a profound impact on cognition. Behavioral states are mediated though the peripheral nervous system and neuromodulatory systems in the brainstem. The noradrenergic nucleus locus coeruleus is activated in parallel with the autonomic system in response to biological imperatives. These responses can be spontaneous, to unexpected salient or threatening stimuli, or they can be conditioned responses to awaited behaviorally relevant stimuli. Noradrenaline, released in forebrain structures, will facilitate sensory processing, enhance cognitive flexibility and executive function in the frontal cortex, and promote offline memory consolidation in limbic structures. Central activation of neuromodulatory neurons and peripheral arousal, together, prepare the organism for a reorientation or reset of cortical networks and an adaptive behavioral response.

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